Process for blowing cupriferous metallic-sulphide melts, especially low-grade coppermattes, direct to black copper



Patented Apr. 12, 1932 UNITED STATES M Hum/[Ann MASCHMEYER, or BAD EMS, GERMANY, nssrenon' To AMERICAN tuner I CORPORATION, or new roux, n. Y., A oonrone'r on -QF,'NEW our:

rnocnss FOR BLOWING cUPnIFEnOUs mmrmesenrmm MEn'rs', EsrncrALLY LOW'-GRADE COPPERMATTES, DIREC T"IO BLACK COPPER No Drawing. Application filed April 20, 1931, SerialNmfiBliGOS, and in Germany April 30, 1930;

This invention relates to a process for blowing cupriferous metallic-sulphidemelts, especially low-grade'copper mattes, direct to I black copper.

The blowing of copper matte in the converter has hitherto been performed by blow ing air through the molten matte in such quantity to burn off the sulphur compounds of the iron, copper and the like, as quickly as possible, and solely by utilizing the resulting heat and the heat generated by the formation of the slag.

Since considerable quantities of heat are consumed by the heat losses due to radiation and the like, and by the endothermic reaction between Cu2S and 011 0. at the end of the operation, whereby the bath is liable to solidify, the blowing in the converter must be effected as rapidly as possible. This, however, gives rise to considerable drawbacks, inasmuch as the converter discharges extensively, and also because, owing to the resulting high temperature ferro or ferrosoferric-silicates, or even ferrite are formed instead of ferrous silicate, whichrender the fusion of the slag difficult. Consequently, the yield of copper is greatly impaired. If, in addition, plumbiferous mattes are present, the bulk of the lead will be volatilized, and must be recovered by roundabout ways from the flue dust.

These drawbacks are obviated by the proc ess of the present invention, according to which the blast air is so controlled,'in blowing, that, in contrast to the existing process, the oxidation of the oxidizable constituents proceeds gradually, the duration of the proc ess being thus increased to at least double the time hitherto required. The resulting heat deficiency is balanced, according to the present invention, by auxiliary heating. The

result of such a procedure is that the process is carried on slowly and'quietly without any of the reaction is that only small. quantities "copper being. therefore substantially improved. This increased yield of copper-can, be further augmented by the inclusionofa settling stage prior to tapping; the slag, during which the blowing is suspended, andjthe auxiliary heating is maintained solely in order to keep the bath in a fluid-condition.

Another substantial advantageof thepres} ent process is that, during its gradual passage through the bath, the atmospheric oxy gen .i-s' more fully utilized than in. the case of the'known processes. I

The process is also particularly suitable in connection with the utilization of. the efliuent gases for sulphuric acid manufacture, since "the blast apparatus can'be com-- pletely enclosed, thus keeping out? the un avoidableiadj acent' air, whichhas always to be taken into account in the present blowing in ,the converter; As the result of thisand the more complete utilizationoflthe blast air, substantially; more concentrated efliuent seswb ai da;

The process is particularly adapted for blowing low-grade copper mattes, which could not hitherto be blown direct, since larger quantities of slag are produced, which couldnot be kept in a sufliciently fluid condition. j i

The existing practice consisted in roasting these low-grade mattes and then subjecting them to a concentrative smelting in a shaftor reverberatory furnace, in order to raise the copper content to'the degree (35-40% of Cu) considered necessary for blowing.

In blowing low-grade copper mattes inaccordance with the present invention, this preliminary treatment is dispensed with, the crude, low-grade matte being poured in the molten condition .direct'from the crude-ore furnace into the blower, and blown slowly,

with addition of suitable slagging agents.

When a certain amount of slag has been formed, the blast may be safely suspendedp the auxiliary heating being. maintained-e the charge'left to settle,'and the slag tapped off. If desired, afresh quantity of matte,

and additions, may then be introduced and the blowing continued until the furnace is full of concentrated matte, which can then be blown to completion in the same, or another apparatus.

According to the process, mixed ores or mattes, containing copper sulphide and resulting from some other than a decidedly cope per-works process, can also be worked up.

directly to black copper by blowing.

The process can be carried out in any type of blowing apparatus that is provided with auxiliary heating means and operated with solid, liquid or pulverized fuel, or in any con Venient manner.

Claims 1. A process for the direct blowing of cupriferous metallic-sulphide melts to black copper, which comprises slowly bubbling air through the bath to effect a gradual oxidation of the oxidizable constituents and at the same time maintaining the bath in molten condition by auxiliary heating.

2. A process for the direct blowing of lowgrade copper matte melts to black copper, which comprises slowly bubbling air through the bath to eflect a gradual oxidation of the oxidizable constituents and at the same time maintaining the bath in molten condition by auxiliary heating.

3. A process for the direct blowing of cupriferous metallic-sulphide melts to black copper, which comprises slowly bubbling air through the bath to efi'ect a gradual oxidation of the oxidizable constituents and at the same time maintaining the bath in molten condition by auxiliary heating andthereafter allowing the bath to settle while maintaining the auxiliary heating.

' In testimony whereof, I affixemy signature.

HERlVLANN MASCHMEYER. 

